The prevalence of chronic insomnia increases with age. Recent findings demonstrate that in addition to its detrimental effects on cognition and performance, sleep loss also has a negative impact on health, that is similar to age-related changes in metabolic, cardiovascular and immune measures of health. Despite the important medical and social consequences of chronic sleep loss that accompany the aging process, there is a paucity of safe and effective treatment strategies for the elderly. The chronic nature of the sleep problems, coupled with the side effects of hypnotic medications, limit the usefulness of pharmacological approaches for the treatment of insomnia in this older population. Therefore, there is a need to develop alternative, safe and effective approaches for the management of insomnia in older adults. Recent findings indicate that exercise can improve sleep quality in older adults. The goal of the proposed research is to determine the ability of exercise to improve sleep, health, daytime performance and overall quality of life in older adults with insomnia. Specific aim 1 is to determine the effects of exercise and sleep hygiene education on objective and subjective measures of sleep quality, sleep quantity, circadian rhythms, daytime performance, mood and quality of life in older adults with insomnia. These objective and subjective measures will be taken during a 3-day admission to the clinical research center before and after a 16- week aerobic exercise program (3-4 sessions per week). The same measures will be taken in a control group before and after a 16-week sleep hygiene education intervention. Specific aim 2 is to determine the effects of the aerobic exercise and improvements in sleep quality and quantity on measures of health. Measurements of metabolic, endocrine, cardiovascular, as well as other biomarkers of aging such as bone turnover, autonomic and immune parameters (IL-6, TNF-alpha and C-reactive protein) will be taken before and after the 16 week exercise intervention or sleep hygiene education intervention. The proposed studies will not only determine whether exercise is an effective approach for the management of insomnia in the elderly, but will also improve our understanding of the relationship between sleep and health in older adults.